SLLR‐MDIC: Spatial log‐likelihood multiuser detection and interference cancelation scheme for OFDM‐IDMA

Abstract

Wireless communication systems have gained huge attraction from research community, industrial, and academic field due to their significant impact on improving the communication efficiency, ease of deployment, and costeffective solution for real-time communication. In this field of wireless communication, cellular communications have grown rapidly due to their daily usages and advantages. This increased demand of cellular communication systems has led to the evolution of 3G, 4G, and 5G communication systems, which in turn demands for higher efficiency and better bandwidth utilization. Due to heavy usage of network communication, multiple users may cause interference which subsequently may lead to the performance degradation which could be addressed using multiuser detection scheme. However, several schemes have been introduced for improving the system performance, but multiple access (MA) still remains a challenging task. Hence, in this work, we present a novel approach called Spatial Log-Likelihood Multiuser Detection and Interference Cancelation (SLLR-MDIC) that uses interleaving division multiple access (IDMA) to improve the communication and developed a multiuser detection approach using spatial log-likelihood ratios. Further, we have developed orthogonal frequency-division multiple access (OFDM)-IDMA-based interference cancelation scheme in multiple access to improve the performance using rake receiver based approach. The performance of SLLR-MDIC scheme is compared with existing techniques of multiuser detection in terms of biterror rate (BER) and symbol error rate (SER). The experimental analysis shows that proposed approach achieves improved performance when compared with existing techniques.

A Novel Multiuser Detection and Channel Estimation Method for Uplink Communication in MIMO-OFDM IDMA System

“…are the significant research components of IDMA. Sharma et al [11] introduced an approach for multi-user detection and interference cancellation in IDMA. According to this approach spatial log-likelihood multiuser detection is carried out and tested for MIMO-IDMA systems.…”

“…Recently, interference cancellation and multiuser detection techniques are adopted to mitigate the effect of interference, MAI and MUD [11]. According to these schemes, detector considers the multipath signal and detects each signal individually by computing log-likelihood ratios (LLRs).…”

“…The IDMA systems are considered as a promising technique to improve the communication performance. The IDMA based models are used in MIMO [9], NOMA [10], and OFDM [11] etc. The IDMA systems have significant impact on 5G communication where huge numbers of users are present.…”

“…However, these systems achieve poor performance for multi-path fading scenario because multiple paths reduce the convergence capability of ESE. In order to overcome this issue multiuser detection schemes are developed [11] [14][15][16][17]. Compared to CDMA, multiuser detection algorithms are easy to implement in IDMA systems.…”

“…Channel estimatorAfter considering the transmitted signal from user as and pilot . The received signal can be represented as:(11) …”